Parents who are not married are four times more likely to split up than those who have wed, according to a new 
study from the UK.
The study also showed that co-habiting couples with children under 16 are now responsible for the majority of family breakdowns although they make up just a fifth of all couples.
On average, 5.3pc of these relationships ended each year from 2009-12, according to the study, the Daily Mail reports.
But among those who had taken their vows, the average rate was only 1.3pc, according to figures gathered from the findings of a £50million state-sponsored research project, the Understanding Society survey.
The survey was commissioned by the Marriage Foundation, a think tank set up to promote and strengthen marriage.
Results were compared with findings from the official Labour Force Survey, which asks questions in around 15,000 households.
On current trends, 61,700 unmarried couples with children will split this year, compared with 60,600 married couples. It means 2013 will be the first year in which the divorce of married couples is no longer the main cause of the break-up of families with children aged under 16.
Harry Benson, of the Marriage Foundation, said: ‘This marks a tipping point for society.
‘We have an epidemic of family breakdown because so few people realise how badly the odds of success are stacked against unmarried co-habitees.
‘If you’re living together as unmarried parents, you’re four times more likely to split up than married parents.
‘It is frequently said that low income and poor education are the main reasons behind family breakdown. But, if anything, the average income and level in education has improved since the 1980s while family breakdown has doubled.
‘We haven’t been getting poorer or less well-educated but we have become less willing to commit to our families.
‘The link between declining numbers of marriages and increasing levels of family breakdown is plain for everyone to see.’ According to calculations by the foundation, which worked with academics from the University of Lincoln, the figures indicate that 116,800 couples with children under 16 separated in 2010.
Of these family breakdowns, 60,400 involved married parents and 56,400 co-habiting couples. The study’s figures are a close match with those from the Office for National Statistics, which said there were 59,309 divorces involving children under 16 in 2010.
Researchers applied these break-up rates to population data for 2013 and suggested that co-habiting parents may now account for more than half of family breakdowns.
Last month, the Institute for Fiscal Studies said it was wrong to suggest two years ago that marriage itself had no bearing on whether or not couples break up.
The think-tank admitted that money, education and social factors alone do not explain family failure.